Micofabricated Cantilever-Based Scanner for forward-looking 3D Endoscopic Optical

描述（由申请人提供）：本项目旨在开发一种新型二维光学扫描仪，以实现内窥镜前视三维光学相干断层扫描。内窥镜OCT（EOCT）通过在各种组织中原位进行断层扫描亚表面成像的“光学活检”提供了微创诊断的可能性。基于导管的EOCT是通过将光束输送通过放置在内窥镜内的导管来执行的。导管OCT探头是使用侧视几何结构开发的，适用于窄腔血管成像。前视探头将极大地增强对诸如胃、结肠和膀胱的大的或中空的器官的粘膜成像的能力，但是由于导管尺寸的限制，实现方式是复杂的。已经报告了实现前瞻性EOCT的方法，并且由于难以在小导管直径（2.9 mm）内插入二维光学扫描仪，通常提供一维扫描。给定导管集成的二维光学扫描仪，可以使用纵向尺寸扫描来获得高分辨率3D EOCT成像，其中参考光束位于内窥镜外部。这种成像方法将允许对癌症和其他病变进行准确的非侵入性诊断，这些疾病的穿透深度限于上皮层或近上皮层。 本文提出的二维光学扫描器的新设计是基于微加工的悬臂梁。静态偏转和共振频率计算表明，对于一组合理的参数，所提出的方案提供了一个尺寸和功耗优势的竞争方法和出色的扫描范围和速度性能。该项目的重点是导管OCT成像优化的二维扫描仪的微加工和表征。微加工处理步骤将被设计成包括基于致动器几何形状和膜厚度对扫描性能的计算影响而选择的参数范围。将使用一套可用的测量工具表征器械的机械和光学特性。将根据光学扫描仪的实际性能对EOCT系统进行详细的光学模拟。优化的设备将与合适的光学组件集成，并纳入高速傅立叶域OCT扫描仪，以评估图像质量。

DESCRIPTION (provided by applicant): This project aims at the development of a novel two-dimensional optical scanner to enable endoscopic forward-looking 3D Optical Coherence Tomography. Endoscopic OCT (EOCT) provides the potential for minimally invasive diagnostics by "optical biopsy" consisting of tomographic sub-surface imaging in situ in a variety of tissues. Catheter-based EOCT is performed by delivering the light beam through a catheter placed inside an endoscope. Catheter OCT probes have been developed using a side-looking geometry, which is appropriate for imaging narrow-lumen vessels. A forward-looking probe would greatly enhance the ability of imaging mucosa of large or hollow organs such as stomach, colon, and bladder, but the implementation is complicated by the catheter size constraints. Approaches to achieve forwardlooking EOCT have been reported and typically offer uni-dimensional scanning due to the difficulty of inserting a two-dimensional optical scanner within the small catheter diameter (2.9 mm). Given a catheter-integrated, two-dimensional optical scanner, high resolution 3D EOCT imaging can be obtained using longitudinal dimension scanning with the reference beam located outside the endoscope. This imaging approach will allow accurate non-invasive diagnoses of cancers and other pathologies limited in depth of penetration to epithelial or near sub-epithelial layers. The novel design for the two-dimensional optical scanner proposed here is based on microfabricated cantilevers. Static deflection and resonance frequency calculations indicate that, for a reasonable set of parameters, the proposed scheme provides a size and power consumption advantage over the competing approaches and excellent scanning range and speed performance. This project is focused on the microfabrication and characterization of a two-dimensional scanner optimized for catheter OCT imaging. The microfabrication processing steps will be designed to include a range of parameters selected based on the calculated effects of actuator geometry and film thicknesses on scanning performance. The mechanical and optical properties of the devices will be characterized with a suite of available measurement tools. A detailed optical simulation of the EOCT system will be performed based on actual performance of the optical scanner. Optimized devices will be integrated with suitable optical components and incorporated into a high-speed Fourier-Domain OCT scanner to assess image quality.